* Corresponding Author: Tel.: +39 079 229269; Fax: +39 079 229261. E-mail address: ghiglieri@uniss.it.
Abstract
Sustainable water management plays an important role in the frame of the multidisciplinary research activities aim-ing to combat or to mitigate the desertification processes. The study activities have been carried out by RIADE Research Project (Integrated Research for Applying new technologies and processes for combating Desertification, www.riade.net). RIADE was co-financed by MIUR within the National Operative Programme 2000-2006. The pri-mary objective was to explore and to develop models and strategies for innovative and sustainable solutions of wa-ter resources management, adopting a multidisciplinary approach, at the catchment and hydrogeological basin scale in a Mediterranean context, using a case history of a pilot area in NW Sardinia (Italy). The high concentration of population in this coastal zone and the intense agricultural activity have determined a relevant increase of water demand. This demand is generally satisfied by surface water, but, in some peculiar dry periods, it exceeds the avail-able quantities. In these critical periods, groundwater are the only alternative source constituting a strategic water resource. The groundwater chemical properties are then correlated with the effects of the anthropogenic pressures. The used approach shows the application of groundwater protection criteria, in accordance with EU policies, and it was aimed to develop a methodological tool which can be applied to different scenarios.
Key-words: aquifer vulnerability, desertification, hydrogeology, Sardinia-Italy, water management.
Introduction
The Convention to Combat Drought and
De-sertification (UNCCD), adopted during the
Conference of United Nation on Environment
and Development held in Rio, defines
Deserti-fication as “land degradation in arid, semi-arid
and dry sub-humid areas” deriving mainly from
negative human impacts. The word “land” in this
context comprises soil, water resources and
nat-ural vegetation (UNEP, 1994). This definition,
which focuses mainly on soil degradation, may
need an integration related to water resources.
Moreover, the meaning given to the word
“de-sertification”, in common language, is generally
linked to the concept of partial or total lack of
water.
Both from a qualitative and a quantitative
point of view, surface and groundwater resources
are an essential factor for the conservation and
development of any form of life. In fact, they
rep-resent an absolutely indispensable factor for the
survival and the harmonic development of the
natural environments and also for the
socio-eco-nomical growth of the territory.
The deterioration of the water resources,
which have negative impacts on the natural
en-vironments and on the socio-economic growth
of an area, is a key indicator of desertification
(UNEP, 1994; Barbieri et al., 2005; Ghiglieri et
al., 2006, 2009b; http://www.riade.net). Such
de-terioration is actually one of the direct or
con-comitant causes of land degradation, rather than
an effect of the desertification processes
objec-tively noticeable, as in the case of damages
oc-curring in the soils or woodlands.
Sustainable Water Resources Management
to Combat Desertification in the Nurra Region,
Northwestern Sardinia, Italy
Giorgio Ghiglieri
1,3, Giulio Barbieri
2, Antonio Vernier
2, Alberto Carletti
3, Daniele Pittalis
1,31Department of Territorial Engineering, Geopedology and Applied Geology Section,
Desertification Research Group (NRD), University of Sassari, Via De Nicola 9, 07100 Sassari, Italy
2Department of Territorial Engineering, Applied Geology and Applied Geophysics Section,
University of Cagliari, Piazza D’Armi 1, 09100 Cagliari, Italy
3Desertification Research Group (NRD), University of Sassari, Via De Nicola 9, 07100 Sassari, Italy
In the frame of the multidisciplinary
re-search activities for combating and/or
mitigat-ing desertification, a proper water resources
management plays an important role in the
wa-ter conservation in wa-terms of both quality and
quantity (Barbieri et al., 2005; Ghiglieri et al.,
2006, 2009a).
The present study has been carried out in
the framework of the RIADE
1Project
(Inte-grated Research for the Application of
innova-tive technologies and procedures for combating
Desertification) (http://www.riade.net).
One of the aims of the RIADE Project was
to develop models and strategies for innovative
approaches to sustainable water resources
man-agement, at the catchment and hydrogeological
basin scale, applicable in the Mediterranean
ar-eas. Despite the considerable patrimony of
ex-perience and knowledge related to the
deserti-fication processes, only rarely the results of the
studies have been turned into structured and
in-tegrated systems. This is largely due to focusing
on local conditions or individual processes
rather than on their complex interaction. In the
effort for understanding a phenomenon that
in-volves geology, soil science, climatology,
hydro-geology, agronomy and forestry an
interdiscipli-nary synergy is a key issue. A more holistic and
systematic approach to the desertification
processes, by means of an integrated project
such as RIADE, has been developed.
The pilot area for the current study is one
of the areas interested by the RIADE Project.
This area is located in the Nurra plain (Alghero,
NW Sardinia-Italy).
Study area
The Nurra district is located in the northwestern
part of the island of Sardinia (Italy) in the
Sas-sari Province. The study area covers an area of
586 km
2. It is a part of the hydrogeological basin
underlying the Calich coastal lagoon. The area is
divided into two major sectors: the flatlands of
the Alghero plain, in the northern part, and the
rolling landscape that extends from Alghero to
Villanova Monteleone, in the southern part.
Due to intensive human activities and recent
climatic changes, the area has become
vulnera-ble to the desertification processes. The water
demand in the study area is considerable, water
being required for industry, domestic use,
tourism, agriculture, and animal rearing (Dono
et al., 2008). Nurra relies on both surface and
groundwater. The seasonal and perennial rivers
of the area are exploited using the Cuga and
Surigheddu dams, built on the highlands.
How-ever, like in other Mediterranean islands,
sur-face water resources can periodically suffer of
drastic shortage. Groundwater in different
aquifers is exploited using deep boreholes which
can attain discharges as high as 145 l/s.
Notwithstanding the importance of local
groundwater, as the main source of good quality
water, and of their role of strategic reserve in such
semiarid conditions, up to now their exploitation
has been uncontrolled (Barbieri et al., 2005;
Ghiglieri et al., 2006, 2009a). An additional
prob-lem in the Nurra district is that water users have
a very scant knowledge of the provenance and the
value of the fresh water they exploit, thus leading
to a high rate of unofficial exploitation.
The extensive exploitation of the Nurra
aquifers and the consequent water quality
de-terioration require a revision of current water
management practices. This revision has to be
based on a good knowledge of both the
poten-tial of aquifers in terms of geometry and the
storage and the quality in terms of
hydrogeo-chemical characteristics: up to now this
knowl-edge has been disregarded.
The study area presents a complete
strati-graphic sequence ranging in age from the
Palaeozoic to Quaternary rock formations. An
hydrogeological assessment has been developed
using the data collected during the geological
and structural surveys, the geophysical
prospect-ing and a detailed hydrochemical study within
the RIADE Project (Ghiglieri et al., 2006,
2009a). Five main hydrogeological units have
been identified, divided in turn into 7
hydroge-ologic complexes, characterized by
medium-to-high yield (Fig. 1). Groundwater in different
aquifers is exploited using deep boreholes which
can attain discharges as high as 145 l/s (Ghiglieri
et al., 2009a).
1 The RIADE project is co-funded by MIUR (Italian Ministry for Education, University and Research) with-in the frame of the 2000-2006 National Operational Pro-gramme (PON) Research, Development and Higher Ed-ucation. Partners ACS (Advanced Computer System), ENEA (Italian Agency for New Technologies, Energy and the Environment), University of Sassari (Desertifi-cation Research Group).
Materials and methods
This work shows the application of
groundwa-ter protection crigroundwa-teria, in accordance with
na-tional and EU policies, within their integrated
management.
An interdisciplinary methodological
ap-proach has been used to understand in
particu-lar all the geo-information and the human
pres-sure. The study has required multi-source and
multi-scales dataset including hydrogeological
setting, soil map, land use map, groundwater
monitoring data, actual or potential pollution
sources, etc. This activity, which implied also
sur-veys outside the study area, has been
particu-larly time consuming (about 3 years) and
diffi-cult in terms of accessibility and logistics.
For each information a monographic data
sheet has been edited; afterwards data were
or-ganized in a digital database. The method used
in this study for groundwater management
in-corporated a GIS mapping techniques.
Results and discussion
This report refers a synthesis of long lasted
re-search, the main aims of which have been:
– to reconstruct the hydrogeological setting,
the regional groundwater flow and the mean
annual recharge for each aquifer (Ghiglieri
et al., 2006, 2009a) (Tab. 1);
– to ascertain the origin of salinity in
ground-water (Ghiglieri et al., 2006, 2009a);
– to recognise the boundary conditions of the
different hydrogeologic units by mean of
processes that control the concentration of
the chemical major constituents in the
dif-(a)
(b
ferent aquifers (Ghiglieri et al., 2006, 2009a).
The physico-chemical properties of
ground-water sampled in the three monitoring
sur-veys, don’t show many difference in terms of
the main parameters (Tab. 2). The
investi-gated groundwater shows relatively high
Table 2. Statistical analysis of some of the major chemical constituents from groundwaters sampled in December 2004, June 2005 and November 2007 for each aquifer: a) csc(T); b) cc(G); c) ccm(C); d) cpi(OM); e) cmc(Mc).
a) csc (T): limestone, dolomite and gypsum aquifer system
T pH EC Ca2+ Mg2+ Na+ K+ HCO 3- Cl- SO42- NO3- TDS 2004 Min 15,6 6,3 1870 22,00 14,00 122,00 6,50 206,13 258,24 19,67 0,00 1275,93 Max 21,9 8,9 7350 576,00 230,00 1440,00 63,00 582,74 2689,24 1813,18 548,60 5134,30 Ave 18,8 7,0 3480 218,50 99,22 498,26 21,03 376,06 882,54 429,29 79,51 2629,80 SD 1,88 0,62 1552,02 161,33 66,53 386,69 16,61 107,41 693,01 537,78 147,41 1137,33 2005 Min 19,3 6,3 1890 9,00 27,70 94,00 9,75 215,40 220,46 0,00 0,00 1350,97 Max 25,0 8,7 8260 325,00 231,00 1200,00 65,00 623,70 2692,26 874,00 291,38 5134,53 Ave 22,7 7,1 3989 156,95 118,74 490,90 28,48 405,98 948,60 319,81 61,86 2549,16 SD 1,75 0,75 2123,04 95,71 69,66 361,62 17,41 115,92 806,08 270,02 98,11 1203,27 2007 Min 16,7 6,8 1295 1,40 16,00 94,00 4,30 90,31 138,64 18,57 0,33 993,92 Max 20,6 9,3 8690 520,00 240,00 1300,00 51,50 436,70 2901,72 1173,32 132,12 5292,71 Ave 18,3 7,5 4077 191,30 96,75 522,64 20,66 314,37 1054,12 321,94 28,27 2570,87 SD 1,10 0,83 2415,60 149,07 71,46 406,78 16,03 94,55 955,03 331,90 43,54 1424,71
TDS, major cations and anions are in mg/l; temperature (T) is in °C; electrical conductivity (EC) is at 25 °C in µS/cm.
b) cc (G): limestone aquifer system
T pH EC Ca2+ Mg2+ Na+ K+ HCO 3- Cl- SO42- NO3- TDS 2004 Min 15,2 6,4 802 58,00 12,00 42,00 2,25 185,80 85,46 10,51 0,00 656,33 Max 21,6 7,6 2060 248,00 74,00 385,00 20,30 556,11 590,83 395,58 162,40 1588,69 Ave 18,5 6,8 1296 140,89 33,61 123,34 6,02 400,33 219,76 94,50 39,42 1074,58 SD 1,26 0,28 327,94 35,25 13,74 65,52 4,07 73,37 116,81 71,71 29,13 234,72 2005 Min 17,0 6,4 780 53,00 15,20 58,00 3,20 248,80 100,45 23,16 4,37 577,89 Max 24,2 7,5 2280 275,00 68,20 370,00 20,75 570,80 586,34 392,94 136,25 1513,76 Ave 21,0 6,8 1414 134,73 40,04 108,78 8,48 412,51 197,21 91,88 36,63 1044,98 SD 1,84 0,27 384,86 46,03 13,70 65,66 5,12 92,21 111,55 82,99 30,92 253,80 2007 Min 15,9 6,8 811 54,50 14,10 53,00 2,00 240,00 84,74 20,77 0,62 576,79 Max 20,1 7,7 3180 390,00 60,50 360,00 136,00 534,20 594,54 227,12 513,95 2173,28 Ave 17,8 7,1 1469 146,94 32,50 106,65 15,15 410,70 212,55 71,90 50,20 1068,75 SD 1,04 0,22 532,85 63,59 10,94 65,49 28,21 74,01 132,01 44,91 98,10 342,55
TDS, major cations and anions are in mg/l; temperature (T) is in °C; electrical conductivity (EC) is at 25 °C in µS/cm.
Table 1. Mean annual recharge (m3) estimated over 30 years (1961-1990), in 2003, 2004 and 2005 for the whole ground-water basin and for each aquifer.
1961-1990222 2003222 2004222 2005222
Groundwater Basin 37.932.413,92 30.065.157,17 50.309.425,02 35.626.865,46
Aquifer
cme(P) - metamorphic aquifer system 228.739,86 246.706,84 458.094,29 266.366,82
csc(T) - limestone, dolomite and
gypsum aquifer system 3.473.303,32 3.001.686,45 5.279.983,34 3.403.945,29
cc(G) - limestone aquifer system 11.264.766,24 10.525.715,24 19.713.341,58 12.379.228,44 ccm(C) - limestone sequences aquifer system 3.650.683,44 3.200.106,01 5.572.788,44 3.884.339,54 cpi(OM) - pyroclastic aquifer system 16.577.742,40 10.815.989,50 14.990.298,22 12.870.855,76 cmc(Mc) - sandstone and limestone aquifer system 2.664.432,15 2.196.042,66 4.144.197,43 2.809.941,15
c) ccm (C): limestone sequences aquifer system T pH EC Ca2+ Mg2+ Na+ K+ HCO 3- Cl- SO42- NO3- TDS 2004 Min 17,5 6,5 673 46,00 12,50 69,00 2,70 168,93 106,47 38,42 0,00 500,20 Max 21,3 7,8 5140 305,00 135,00 860,00 69,00 658,68 1453,00 300,99 452,54 3513,80 Ave 19,3 7,0 2488 134,02 53,46 376,65 15,54 462,88 588,01 154,70 95,63 1922,09 SD 1,17 0,38 1103,18 65,80 32,73 230,06 14,96 106,94 369,17 76,81 116,09 728,93 2005 Min 20,8 6,6 489 37,03 11,20 49,00 3,20 116,53 100,79 22,62 0,00 374,88 Max 24,4 7,6 5160 285,00 160,00 780,00 56,00 574,20 1258,02 315,20 235,75 3352,45 Ave 22,5 7,0 2424 140,90 65,89 268,90 18,03 426,27 481,99 153,91 71,20 1657,73 SD 1,19 0,37 1434,33 69,46 48,54 218,31 16,91 135,63 406,36 107,53 78,34 872,99 2007 Min 13,0 6,7 422 28,50 7,45 38,00 4,80 91,30 72,52 15,94 0,62 266,73 Max 20,3 7,8 5450 262,00 129,50 880,00 45,00 594,60 1336,62 665,78 226,88 3605,76 Ave 17,7 7,0 2956 155,56 67,26 369,13 16,02 449,23 601,42 224,64 77,11 1997,40 SD 2,68 0,34 1536,68 67,91 42,82 265,64 13,89 174,81 435,44 196,76 94,30 982,14
TDS, major cations and anions are in mg/l; temperature (T) is in °C; electrical conductivity (EC) is at 25 °C in µS/cm.
d) cpi (OM): pyroclastic aquifer system
T pH EC Ca2+ Mg2+ Na+ K+ HCO 3 - Cl- SO 4 2- NO 3 - TDS 2004 Min 13,4 5,7 332 9,00 7,00 43,50 1,60 17,94 61,27 14,97 0,00 226,63 Max 22,4 7,6 4420 428,00 140,00 630,00 24,00 522,79 1273,88 1248,18 133,28 2884,21 Ave 17,6 6,6 1683 67,05 43,09 220,00 10,79 146,18 416,71 100,75 23,51 1096,48 SD 1,97 0,47 1076,24 77,18 35,51 152,86 5,82 115,81 340,48 220,63 30,89 717,93 2005 Min 19,5 6,0 797 19,25 7,65 92,00 7,25 22,00 200,65 31,83 0,00 531,57 Max 24,7 7,0 4630 164,00 176,00 570,00 33,00 469,00 1427,72 239,25 152,37 2948,87 Ave 22,1 6,5 2370 76,93 66,07 295,70 19,06 179,75 647,35 92,45 39,97 1482,80 SD 1,82 0,38 1472,87 49,93 53,49 184,89 9,15 120,12 480,13 65,34 58,24 855,59 2007 Min 16,2 6,1 863 23,00 10,10 108,00 7,30 22,50 207,72 33,39 0,21 551,83 Max 20,6 7,3 4730 156,00 124,00 800,00 23,00 333,60 1479,82 179,69 160,73 2937,91 Ave 18,6 6,7 2461 76,94 55,19 353,11 12,77 156,28 658,25 86,97 41,84 1508,82 SD 1,36 0,40 1557,11 46,47 36,37 238,27 4,96 91,96 484,90 55,67 55,97 865,89
TDS, major cations and anions are in mg/l; temperature (T) is in °C; electrical conductivity (EC) is at 25 °C in µS/cm.
e) cmc (Mc): sandstone and limestone aquifer system
T pH EC Ca2+ Mg2+ Na+ K+ HCO 3 - Cl- SO 4 2- NO 3 - TDS 2004 Min 15,0 6,4 646 94,00 7,00 25,50 1,70 270,37 55,72 16,90 7,45 516,46 Max 18,0 6,9 938 131,00 19,00 57,00 3,20 385,69 110,11 54,91 43,05 775,65 Ave 16,2 6,7 783 113,50 12,00 38,75 2,58 319,70 75,20 34,19 26,68 641,85 SD 1,30 0,24 139,76 16,34 5,43 13,63 0,63 54,22 24,45 19,04 16,98 126,76 2005 Min n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. Max n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. Ave n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. SD n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 2007 Min 17,4 6,8 834 90,00 7,00 31,00 2,10 309,40 70,57 18,30 3,99 645,22 Max 20,3 7,3 3610 380,00 78,50 225,00 16,10 425,90 546,85 201,54 654,62 2473,80 Ave 18,8 7,1 1598 175,43 30,48 111,71 5,97 358,00 243,81 58,69 139,48 1142,25 SD 1,07 0,15 963,22 98,82 25,46 75,99 5,04 42,31 176,94 65,58 229,04 631,86
TDS, major cations and anions are in mg/l; temperature (T) is in °C; electrical conductivity (EC) is at 25 °C in µS/cm; n.d.= not detected.
TDS and chloride concentrations which,
along with other hydrogeochemical
evi-dence, rules out sea water intrusion as the
cause of high salinity. The high chloride and
sulphate concentrations can be related to
deep hydrothermal circuits and to Triassic
evaporites, respectively. The source water
chemistry has been modified by various
geo-chemical processes due to the
groundwater-rock interaction, including ion exchange with
hydrothermal minerals and clays,
incongru-ent solution of dolomite, and sulphate
re-duction (Ghiglieri et al., 2009a);
– to identify and to survey the actual or
po-tential pollution sources (Barbieri et al.,
2005; Ghiglieri et al., 2006, 2008, 2009b);
– to evaluate the potential risk of nitrate
pol-lution in the aquifers from agricultural
prac-tices (Ghiglieri et al., 2009b) by combining
intrinsic aquifer vulnerability to
contamina-tion, according to SINTACS R5 method
(Civita and De Maio, 2000; Civita et al.,
2007), and agricultural nitrates hazard
as-sessment,
according to IPNOA index
(Padovani and Trevisan, 2002). Figure 2
shows the areal frequency distribution of the
SINTACS vulnerability degree in the study
area: the vulnerability classes (M) and (H),
corresponding to medium and high level, are
distributed on 38% of the total area; the
most of the land area is characterized by low
and very low level, accounting for 43% and
18% of the total respectively (Ghiglieri et
al., 2008). Regarding the agricultural nitrates
hazard index (IPNOA) (Ghiglieri et al.,
2009b), the most represented classes are
im-probable (8.7%) and very low (59.9%); low
(3.1%) and moderate (0.05%) (Fig. 3). Five
potential risk levels have been identified
within the catchment area: their areal
fre-quency distribution is shown in Figure 4. As
can be seen, low and moderate classes are
similarly distributed, accounting for 25% and
21% of the total land area respectively. Very
high and high classes occur above all in the
central part of the plain, but affect much
smaller percentages of land area.
Interest-ingly, intrinsic vulnerability in this part of the
catchment basin is high and most of the
po-tential pollution sources are concentrated
therein (Ghiglieri et al., 2009b).
The potential risk areas can be associated
with input-intensive farming (irrigation,
fertil-ization and use of agrichemicals), mainly
vine-yards, market garden and protected crops.
Fur-Figure 3. Areal frequency Agri-cultural Nitrates Hazard (IP-NOA) distribution (modified from Ghiglieri et al., 2006). Figure 2. Areal frequency SIN-TACS vulnerability degree dis-tribution (modified from Ghi-glieri et al., 2006, 2008).
thermore, the area is characterized by a major
industrial agglomeration, two urban centres
(dense residential fabric) and scattered
urban-ization (dispersed residential fabric) (Ghiglieri
et al., 2009b).
Achieving these aims will establish a basis
for developing an appropriate monitoring
pro-gramme and therefore improved management
of the water resources of the region (Ghiglieri
et al., 2006, 2007, 2008).
The multidisciplinary approach, developed in
the RIADE Project, certainly provides
author-ities with a planning tool for water resources
and soil protection, for identifying
desertifica-tion and land degradadesertifica-tion processes and for
for-mulating suitable policies for attenuating
an-thropogenic impact.
Moreover, the experimental data and the
conceptual models developed so far will
consti-tute the basis for the implementation of a
dy-namic simulation model and a decision support
system for integrated environmental
manage-ment.
The study also aimed to gain a better
un-derstanding of desertification processes, in
terms of degradation of water and natural
re-sources and consequently to mitigate its effects.
The approach used here was aimed at
develop-ing a methodological tool which can be applied
to different scenarios.
Acknowledgment
The financial support from Italian Ministry of Educa-tion, University and Research (MIUR) for the develop-ment of the research RIADE (Integrated Research for Applying new technologies and processes for combating Desertification, www.riade.net) is acknowledged. Thanks are due also to Fondazione Banco di Sardegna for the financial support to Mr. D. Pittalis.
References
Barbieri G., Ghiglieri G., Vernier A. 2005. Design of a groundwater monitoring network and identification of environmental quality indicators for combatting desertification. 2ndInternational Workshop - AVR 05 Aquifer Vulnerability and Risk 05 4o. Convegno nazionale sulla protezione e gestione delle acque sot-terranee, Parma 2005 - Atti (ID259), ISBN 88-901342-2-4, GEAM. Rivista IGEA - Ingegneria e Geologia degli Acquiferi [Groundwater Geoengineering] 2006 ISSN 1121-9041, 21:71-80.
Civita M., De Maio M. 2000. SINTACS R5 a new para-metric system for the assessment and automatic mapping of groundwater vulnerability to contamination -Quaderni di Tecniche di Protezione Ambientale, 72, Pitagora Editrice, Bologna, ISBN 88-371-1231-9, 226 pp.
Civita M., Fiorucci A., Vigna B. 2007. The Spatial-Tem-poral Variability of Nitrates in a Section of the Cu-neo Plain (North West Italy). American Journal of Environmental Sciences 3 (3), 111-116, ISSN 1553-345X.
De Maio M., Fiorucci A., Offi M. 2007. Risk of ground-water contamination from nitrates in the Po basin (Italy). Water Science & Technology: Water Supply Vol. 7, N. 3, 83-92, © IWA Publishing 2007, doi 10.2166/ws.2007.070.
Dono G., Marongiu S., Severino S., Sistu G., Strazzera E. 2008. Studio sulla gestione sostenibile delle risorse idriche: analisi dei modelli di consumo per usi irrigui e civili [Sustainable water resources management: cri-teria water consuption models for irrigation and civ-il use], ISBN 88-8286-155-4, 257 pp.
Ghiglieri G., Barbieri G., Vernier A. 2006. Studio sulla gestione sostenibile delle risorse idriche: dall’analisi conoscitiva alle strategie di salvaguardia e tutela [Sus-tainable water resources management: knowledge and protection criteria], ISBN 88-8286-147-3, 550 pp. Ghiglieri G., Barbieri G., Vernier A., Carletti A., De-murtas N., Deroma M., Pinna R., Pittalis D., Vigo A. 2007. Carta idrogeologica e rete di monitoraggio cor-pi idrici superficiali e sotterranei Nurra (Sardegna Nord-Occidentale). Scala 1:50.000. ISBN 88-8286
Ital. J. Agron. / Riv. Agron., 2010, 3 Suppl.:7-14
Figure 4. Areal frequency dis-tribution: Potential Risk of ni-trate pollution in aquifer from agricultural practices (modified from Ghiglieri et al., 2006).
Figure 4
Stampa Composita [Hydrogeological Map of the Nurra area (NW Sardinia): surface water and groundwater monitoring network. Scale 1:50.000. Ed-it by ComposEd-ita].
Ghiglieri G., Barbieri G., Vernier A., Carletti A., Dore M., Demurtas N., Pinna R., Pittalis D., Vargiu M. 2008. Vul-nerabilità all’inquinamento degli acquiferi della Nurra di Alghero (SS) per la gestione integrata delle risorse idriche (Sardegna NW) [Aquifer vulnerability in the Nurra Region (Alghero) for integrated water resources management: NW Sardinia]. Rivista IGEA - Ingegne-ria e Geologia degli Acquiferi [Groundwater Geo-engineering], ISSN 1121-9041, 23:77-86.
Ghiglieri G., Oggiano G., Fidelibus D., Barbieri G., Vernier A., Tamiru A., 2009a. Hydrogeology of the Nurra Region, Sardinia (Italy): basement - cover in-fluences on groundwater occurrence and hydrogeo-chemistry. Hydrogelogy Journal Springer Verlag, ISSN 1431-2174, Vol. 17, Issue 2, 447-466.
Ghiglieri G., Barbieri G., Vernier A., Carletti A., De-murtas N., Pinna R., Pittalis D. 2009b. Potential risks of nitrate pollution in aquifers from agricultural prac-tices in the Nurra region, northwestern Sardinia, Italy. Journal of Hydrology, ISSN 0022-1694, Vol. 379, Issues 3-4, 339-350.
Padovani L., Trevisan M. 2002. I nitrati di origine agri-cola nelle acque sotterranee [Nitrates of agricultural origin in groundwater]. Quaderni di Tecniche di Pro-tezione Ambientale, Pitagora Editrice, Bologna, IS-BN 88-371-1260-2, 75: 103 pp.
RIADE Project 2003-2006. Integrated Research for Ap-plying new technologies and processes for combat-ing Desertification, http://www.riade.net.
UNEP 1994. United Nations Convention to Combact Desertification in those countries experiencing seri-ous drought anf/or desertification, particularly in Africa. UNEP, Genève.
